NSU Helmet Stencil Factory Guard, Security, Air Defence & Fireman's Helmet Stencil
During World War II NSU designed and produced the Kettenkrad, the NSU HK101, a half-tracked motorcycle with the engine of the Opel Olympia. It was acquired by Volkswagen Group in 1969. VW merged the company with Auto Union, to eventually evolve into Audi as it is known today. This stencil marking would have been worn on the helmets of NSU employed personnel, air defence, Fire units and Security guards.